Exemplary embodiments herein generally relate to a vehicle frame assembly, and more particularly, to a tri-layer frame structure for increased stiffness and load capability.
Box or squared shaped structures of a vehicle frame assembly can have unstable sidewalls that collapse and buckle during crash events. However, such frame structures are easy to manufacture and are conducive to assembly and welding processes. Because the sidewalls of these frame structures can lack strength, once the sidewalls have buckled, they easily fold over and deformation occurs. This is especially apparent in frame structures where an input load causes a pre-existing bend (due to layout or clearance requirements) in a frame member to fail because of sidewall buckling. Current designs for the box shaped frame structure can use a two-layer laminated patch which spans between adjoining frame structures. However, this two-layer laminated patch does not evenly split a load and, the sidewall can collapse and deform due to inadequate strength and stress concentration.